I think your wife is correct when she says "not much bigger" but it is bigger. Now, if you want real comfort then get an X5. I have an F10 and an X5 and we take the X5 when we want to be comfortable

I shouldn't really admit this in the 5er forums, but by far the car I have enjoyed the most as a passenger when hitting a nice steak house is my buddy's 750Li. I know getting a 7 bumps you to a higher price point, but there is so much room in that vehicle I don't know how there could be anyone that complains about its space. And it has fairly nice giddy-up too. It's really a nice cruiser.